Broaching machine



April 17, 1.945. o. w. BONNAFE 2,373,995

BROAGHING MACHINE File'd Jan. 25, 1944 ZSheets-Sheet 1 INVENTOR. 0612bMbonnge,

BY ATTORNEY April 17, 1945. o. w. BONNAFE BROACHING MACHINE Filed Jan.25, 1944 2 Sheets-Sheet 2 Patented Apr. 17, 1945 i umrreo STATES. OFFICEk 2-,s7s,995; 'i i BaoAcHINc Oliver (W -B'onnafe; Hudson, Mass, assignorto l l The La F'ointMachine Tobl compans fludson, .Mass.,1 a.corporation of Maine. Applicat on.ran myzs,1944,,'serialin tisgcvi;

z GLClhirns. (01. 90-33) I "This invention relates to a work holderparticularly designed for use in broaching machines.

Itis'the general object of my invention to provide a holder in whichtubular work may be conveniently supported and-moved fromloading'position to broaching position and vice-versa.

A further object isto provide a work holder in which a'broach-returntube is moved into operative position'as the work is moved to loadingposition. I also provide improved operating means for moving the workholder, and? improved devices for-centering the work'and supplyinglubricant thereto. A preferred form of the'invention is shown inthe-drawings, in which Fig. 1 is a plan view of my improved work holder;

Fig. 2-is-a front elevation,"partly in section, looking in the directionof the arrow 2 in Fig. 1:

Figs. 3, 4, and 6 are transverse sectional views,

taken along thelines 33, 4- 4, 5- 5" and'6-f6 respectively in Figs; 1and 2;'and

Fig. '7 is an enlarged side elevation-of certain parts appearing in Fig.2.

Referring to the drawings; my improved work holder comprises a tubularmain "shaft (Fig; 2) having a bearing at the head end-in a fixed plate Hand at the opposite end in a fixed cross gi'rt l2. Work supportingbrackets I4 (Figs.' 1 and 5) are clamped'in spaced relation on the mainshaft l0 and are provided with screws I5, I6' and I! (Fig. 5) which maybe adjusted to" engageand center a piece of tubular'wo'rk Wof anydesiredsize within the capacity of the machine. Itwill be understoodthat as many-of the brackets Htare supplied as may be necessary for thework I to: be handled. Each bracket I4 is provided with e a clampingportion ZO-to receive and bold are turn tube 2|, which tube is of suchinternal diameter as will permit the breach toslide freely therethrough.

A swinging head plate. 24 (Figs. 2 and 3) is keyed to the main shaftIll. The end of the 'shaft extends beyond the plate 211 and is-rotatab1ysup-- ported in a bushing in the fixed plate ll. The

swinging plate 24 receives one "end: of the return tube 21 and has anopening therethrough aligned with the tube. .Theplate 24 also has aholding chuck 26' to receive and center one end ofjthe work W which issupported and positioned by: the screws,:l5, wand llin'the brackets l4.A guide 21 on the fixed plate H holds the swinging plate 24 in slidingengagement therewith, and stops 28 and 29 limit swinging movement of theplate 24 in both directions.

The means for swinging. the plate 24 and. the work. "support associatedtherewith. comprise a piston" 30,; (Fig. 3).slida ble .in a. cylinder 3!and connected by. afrod 32. to a slide 33. which slide in; turn is.connected by a link 34 to the lower end of 'the plate 24. Admission ofoil under pressure to one end or the other of the cylinder 3| willswing/the plate 24 from the operative. position shown Fig.1 3*to theloading and broachreturnpos'ition in which theplate 24 engages the stop29, or vice versa.

A suitable'hollow casingmemberor trough 3.6.

extendsfthe length of the. machine and encloses the, working. parts on;three sides thereof, as clearly 'shownin' Figs. 3. to 6. When the workWand chuck 26 are in breaching position, the work is. aligned with thebroach. puller head 46 shown bef'36; and, to which, guideways the crossgirt l2 (Figs, 1. and 4). is also secured.

The carriage 5| may be moved longitudinally. of'the machine by means ofa hand wheel 54 (Fig. 1)conne,cted by a. shaft'55 (Fig. 6) to a sprocket51 (Fig. 2) supported in a fixed bracket 58. A 'similar' sprocket5,9ismounted in a second fixed bracket 60,. and the sprockets 51 and59'.

support a" sprocket chain 6| to which the tail: carriage 5| is secured.By turning the hand wheel 54. the chain, may be moved longitudinally toadvance or retract the carriage 5.1 with respect to the'workW.

A ratchet 63 isfixed to. the shaft 55 and is engagedj by a pawl 64mounted on, a pivot 65 on the j casing member 36. [The pawl is providedwith a knob '66 by which it may be lifted to release. the

ratchet.

' 'A spring 10 is inserted between the rearend of the tail center illand a shoulder in the carriage 5|. Longitudinal movement of the tailcenter 50in the carriage 5! i limited by a stud 1|;(Figg 2 extendinginto/. short notch 12 inthe: tail center 50.

When the carriage and tail center are movedv u'p'by thehand'wheel54;.the tail center will engage the endof' the work W and the spring 10may. then be compressed until the latch 64 drops into a notch in theratchet 53, thus holding the tall center with yielding pressure againstthe end of the work to center and support the same.

A tubular extension 15 is slidable in the rear end of the tail center 50(Fig. 7) and is closed at its outer end by a plug 16. The tubularextension 15 is clamped in a block 17 slidable on a guide-rod 18extending rearward from the carriage When the parts are aligned as shownin Fig. 6, the tubular extension may be advanced into the rear end ofthe tail center 50 and may be secured by a hand lever 80 which isconnected by links 82 to the carriage 5|. When the lever 80 is swung tothe left in Fig, -1, the spaced ends of the lever will engage studs 83(Fig. 7) in the extension 15 and will force the part 15 firmly into thetail center 50, Where it is held by the toggle action of the hand lever80 and links 82. A tight connection is thus established between theextension 15 and the tail center 50.

The machine and work holder are operated as follows: After a piece ofwork W is completed and the broach has cleared the right-hand end of thework and the swinging plate 24, the hand lever 80 is swung to the rightin Fig. 2 to release the tubular extension 15, which may then bewithdrawn by sliding the block 11 rearward along its guide rod 18. endof the extension 15 clears the carriage 5!, the block 11 may be swungsiclewise, so that it s M will not axially obstruct the return of thebroach i through the hollow tail center.

Fixed studs 90 act as stops to limit the swinging movement of the block'17. The holding pawl 64 is then released and the carriage Si is movedto the left in Fig. 2 far enough to clear the adjacent end of the workW.

Pressure is then admitted to the cylinder 3! to swing the plate 24 andthe work holder to the left in Fig. 3 to align the return tube 2| withthe breach and puller head 40. The broach may then be returned to theleft through the tube 2| and the hollow tail center 50, and a new pieceof work may be inserted in the supporting brackets l4 and chuck 26.

Pressure is then admitted to the opposite side of the cylinder 3! toreturn the work holder to the position shown in Fig. 3, after which thetail center 56 is advanced to engage and center the work, and thereduced puller end of the broaoh is pushed through the work until itengages the puller head 40, in which position the breach itself isdisposed in the hollow tail center 50 or may even extend somewhat to theleft thereof.

The tubular extension (5 is then swung into alignment with the tailcenter 50 and is pushed forward to the position shown in Figs. 2 and 7,in which position it is secured by the toggle action of the lever 80 andlinks 82. The machine is then in condition for the next breachingoperation, during which oil under pressure will be supplied to the tailcenter 50 through a supply pipe 79. After flowing through thelongitudinalchannels between the lands of the broach, the lubricant isdischarged into the casing or trough 36 at the right-hand end of thework.

I have thu provided a work holder by which long and heavy pieces of workmay be conven iently supported for broaching and having provision bywhich the work may be swung to loading position, while at the same timethe return When the right-hand movement of the breach is guided by areturn tube operatively aligned.

Having thus described my invention and the advantages thereof, I do notwish to be limited to the details herein disclosed, otherwise than asset forth in the claims, but what I claim is:

1. In a work holder for a broaching machine, a fixed supportingstructure, a hollow tail center movable along a fixed axis in saidstructure to engage and center the work when the latter is in broachingposition only, a slidaible carriage for said tail center, a tubularextension insertable in the rear end of said tail center, a support forsaid tubular extension on which said extension may be moved transverselyout of alignment with said tail center and means to seat and clamp saidtubular extension in said tail center, said hollow center and tubularextension housing the broach prior to the broaching operation.

2. The combination in a work holder as set forth in claim 1, in whichthe tubular extension is seated and secured in said tail center by ahand lever having a link connection to said slidable carriage and havinga toggle action on said tubular extension.

3. In a work holder for a breaching machine, a hollow tail centermovable axially in said work holder to engage and center the work whenthe latter is in broaching position only, a slidable carriage for saidtail center, a tubular extension insertable in the rear end of said tailcenter, means to seat and clamp said tubular extension in said tailcenter, and means to support said tubular extension for transversedisplacement relative to said tail center when withdrawn therefrom.

4. In a work holder for a breaching machine, a hollow tail center, acarriage for said tail center, means to move said carriage to advanceand seat said tail center against the end of a piece of tubular work, aremovable rear tubular extension for said hollow tail center, means toseat said extension in said tail center to seal the rear end thereof,and means to supply lubricant to the tubular work and broach'throughsaid hoL low tail center.

5. A work holder for a broaching machine comprising a supporting member,means to support a piece of tubular work and a broaoh return tube inparallel spaced positions in said supporting member, means to oscillatesaid supporting member to present said tubular work and said return tubealternately in the same operative position, a hollow tail center tosupport and center the work when the work is in breaching position only,said tail center being slidable along a fixed longitudinal axis whichcoincides with the axis of the work when the work is in breachingposition, and means to supply lubricant to the tubular work and breachthrough said hollow tail center when thus positioned.

6. The combination in a' work holder for a breaching machine as setforth in claim 5, in which the oscillating means comprises a hydrauliccylinder and piston having relative movement and a link connecting saidsupporting member to the movable hydraulic part for oscillation therebybetween breaching and loading positions.

OLIVER W. BONNAFE.

